Field
Embodiments of the present disclosure generally relate to layered double hydroxide materials, and specifically relate to high aspect ratio layered double hydroxide materials and methods for preparation.
Technical Background
The synthesis of supported metal or metal-oxide catalysts is of great industrial importance in heterogeneous catalysis. High activity, high selectivity, and long catalyst life are desirable characteristics of any industrial catalyst. Catalyst materials may be produced from layered double hydroxides (LDHs). LDHs, which are also known as anionic clays, are inverse charge analogues of the widely used aluminosilicate cationic clays in their structure and properties. Though a number of methods exist to prepare metal oxide particles in general, oxides obtained by decomposing LDHs have several advantages compared to oxide particles obtained by synthetic methods such as wet impregnation/solid state preparation. Specifically, LDHs may provide a simple, cost effective and environmentally suitable way to achieve a homogeneous distribution of metal ions at the atomic level. In order to make use of LDH layers for various applications, one needs to be able to exfoliate or delaminate these layers. Since carbonate LDHs are thermodynamically more stable, it is difficult to exchange it for other ions or to exfoliate LDH layers where carbonate is the charge balancing ion. As a result, these materials have limited usage. There have been attempts to prepare high aspect ratio non-carbonated LDHs starting from carbonate LDH; however, this approach has multiple steps and is cumbersome.